Automatic reclosing circuit breaker system



J i 1934- A. E. ANDERSON ETAL I 1,968,629

AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Filed Nov. 26, 1932 Fig. 3.4/ 39 4 321 m Hi 30 5/ g Fig.2. s 2'7 Inventors Arvid E.Ander-son,

Vernon L. COX

Fred 8 .WriQhtQ Their Attorney.

effected as quickly as UNITED STATES PATENT orrice AUTOMATIC REOLOSINGcmomr BREAKER SYSTEM Arvid E. Anderson, Drexel Hill, and Vernon IL.

Cox, Lansdowne, Pa., Kingsport, Tenn, assi Company,

and Fred S. Wright,

gnors to General Electric a corporation of New York Application November26, 1932, Serial No. 644,470 13 Claims. (Cl. 175-=-294) Our inventionrelates to automatic reclosing circuit breaker systems and particularlyto such systems in which the initial reclosure of the circuit breaker,upon the occurrence of an abnormal condition which eifects the openingthereof, is

opening thereof and if any,

possible after the initial the subsequent reclosures, areeffected onlyafter the circuit breaker has remained open for relatively longintervals of time. desirable minimum rupted since most of the faultswhic in practice in order to Such arrangements have been found reduce tog a the length of time service is interhcause a circuit breaker to openare of such a character that they cease to of the circuit breaker.

exist after the initial opening One object of our invention is toprovide an improved automatic reclosing circuit breaker system of theabove type and particularly a simcircuit arrangement or substantiallyinbreaker after understood from n connection with the accompanyingdrawing and its scope will be pointed out in the appended claims.

Referring to the accompanying drawing, Fig. 1 diagrammaticallyillustrates an automatic reclosing circuit breaker employing ourinvention and Figs. 2 and 8 illustrate modifications of of that system.

portions Referring to Fig. 1, 1 represents a suitable circuit breaker,examples of wh known in the art, for connecting a 2, which may besupplied from ich are well supply circuit any suitable source, to a loadcircuit 3. As shown in the drawing, the circuit breaker l is of th ewell-known latched-in type and comprises a closing coil 4, which, whenenergized, closes the circuit'breaker 1, a latch 5 for holding thecircuit breaker in its closed position and a trip coil 6 which, whenenergized, releases the latch 5 and allows the circuit breaker to open.Although the circuit breaker 1 is preferably not essential of the trip-Iree type, examples of which are well known in the art, whereby theenergization of the trip coil 6 while the closing coil 4 is stillenergized allows the circuit breaker to open and whereby the circuitbreaker cannot be reclosed thereafter until the closing coil has beendeenergized and subsequently reenergized. When a trip-free breaker isused a suitable latch-checking switch is provided in order to preventthe breaker from being reclosed until after the latch has been reset.

Any suitable fault responsive means, examples of which are well known inthe art, may be proon vided for effecting the opening'of the circuitbreaker 1. As shown in the drawing, the fault responsive means includesthree over-current relays 'Z, 8 and 9 which are respectively connectedin series relation with different phases of the supply circuit 2. Therelays 7, 8 and 9 are provided with contacts 10, 11 and 12 respectivelywhich are connected in parallel with each other and in series with thetrip coil 6 and the auxiliary contacts 13 on the circuit breaker 1 sothat an energizing circuit for the trip coil 6 is completed to eifectthe opening of the circuit breaker when the current in any phase of thesupply circuit 2 exceeds a predetermined value. While the relays 7, 8and 9 may be either instantaneous 7 or time delay closing, preferablythey are of 5 the quick reset type.

For efiectinga single instantaneous reclosure of the circuit breaker 1after the initial opening thereof in response to an abnormal load condi-0 tion on the load circuit, we provide a control device 15 which, asshown in the drawing, comprises two electromagnets l6 and 17 and a latch18 for maintaining the magnet 17 in its energized position, said latch18 being arranged to "be tripped by the magnet 16 when it is energized.Under normal operating conditions the magnet 1'7 is held in itsenergized position by the latch 18 and in that position the contacts 19are closed and the contacts 20 and 21 are open. Also under normaloperating conditions the magnet 16 is deenergized so that its contacts22 and 23 are open.

The winding 24 of the magnet 16 is connected in series with the normallyclosed contacts 19 and the auxiliary contacts 25 on the circuit breaker1 when it is open so that, as soon as the circuit breaker 1 opens-themagnet 16 is energized to close its contacts 22 and 23 and also to tripthe. latch 18 so that the contacts 19 are opened and the contacts 20 and21 are closed. The closing of the contacts 23 completes a lockingcircuit for the Winding 24 of the magnet 16 so that it remainsenergized, after the opening of the contacts 19, until the circuitbreaker 1 closes and opens its auxiliary contacts 25; The closing of thecontacts 22 and 20, which are connected in series, completes anenergizing circuit for a control relay 26 which, in turn, completes anenergizing circuit for the closing coil 4 of the circuit breaker 1. Assoon as the circuit breaker 1 closes, the magnet 16 becomes deenergizedand opens its no fore, the magnet 16 cannot be energized again 5 untilthe winding 27 of the magnet 17 is energized to eflect the closing ofthe contacts 19. Consequently, if the circuit breaker 1 should openinnnediaely after its first reclosure, the circuit breaker is preventedfrom being reclosed in: stantaneously thereafter for a predeterminedtime. Suitable means are provided, aswill be hereinafter described, forveffecting the energization of the winding 27 of the magnet 17 if thecircuit breaker 1 is closed at the expiration of a predetermined timeinterval after a reclosure thereof.

In order to effect the reclosing of the circuit b eaker 1 apredetermined number of times with r latively long predetermined timeintervals between successive reclosures in case the circuit breaker doesnot remain closed after the initial instantaneous reclosure, and inorder to limit the number of such time delayed reclosures, we provide asuitable motor-operated reclosing device 27', examples of which are wellknown in the art. As shown in the drawing, this reclosing devicecomprises a timer 28 and a substantially constant speed driving motor 29therefor, which is permanently connected to a suitable source of currentsuch as the supply circuit 2. The motor 29 is normally prevented fromrotating by a stop 30 which engages a projection 31 on the timer 38. Thestop 30 is arranged to be moved out of engagement with the projection 31by a release magnet 32 when it is energized. The winding of the magnet32 is connected in series with the contacts 21 of magnet 17 and contacts33 of the control relay 26 so that when relay 26 is energized, to efiectthe initial reclosure of the circuit breaker 1, it also effects theenergization of the release magnet 32 to start the reclosing device 2'?into operation. In certain cases contacts 33 may be omitted from thiscircuit.

The timer 2'7 is provided with two sets of cantacts 34 and 35 which arearranged to be closed successively, as the timer rotates withpredetermined time intervals between successive closures thereof. Thecontacts 34 and 35 are also arranged so that only one set can be closedat any instant. When the contacts 34 are closed, a circuit is completedfor a control relay 36 associated with the timer 28 if atthe same timethe circuit breaker 1 is open so thatits auxiliary contacts 25 areclosed. Therelay 36, when energized, completed a locking circuit foritself so that the relay remains energized when the contacts 34 aresubsequently opened. When the contacts 35 are closed and the relay 36 isalso energized at the same time, a circuit is completed for the controlrelay 26 to establish an energizing circuit for the closing coil 4 ofthe circuit breaker 1.

After the timer 28 has been in operation for a predetermined time andthe contacts 34 and 35 have been closed a predetermined number of times,the timer is arranged to interrupt the connection between contacts 39and 40 and to establish a connection between contacts 39 and 41. If thecircuit breaker 1 is closed at the time the contacts 39 and 41 areconnected together, a circuit is completed for the winding 2'7 of themagnet 1'? so as to restore it to its energized or normal position inwhich position it is held by the latch 18. If, however, the circuitbreaker is open at the time the contacts 39 and 41 are connectedtogether, the magnet 1'7 remains deenergized and no further automaticreclosing of the circuit breaker can take place until after a suitablemanual operation, such as the movement of the magnet 17 to its energizedposition, has been performed.

The operation of the arrangement shown in Fig. 1 is as follows: When thecircuit breaker 1 is closed, it is held in its closed position by thelatch 5 as long as conditions on the load circuit are normal. When anabnormal condition occurs which causes one of the overcurrent relays toclose its contacts, a circuit is then completed through the auxiliarycontacts 13 on the circuit breaker and the contacts of the operatedovercurrent relay for the trip coil 6 to effect the opening of thecircuit breaker 1. By opening its auxiliary contacts 13 the circuitbreaker 1 interrupts the circuit of its trip coil 6 so that the spring46 restores the latch 5 to a position in which it is operative tomaintain the circuit breaker 1 in its closed position when it issubsequently reclosed. As soon as the circuit breaker opens, itsauxiliary contacts 25 complete, through the contacts 19 of the magnet 17and thecontacts 39 and 40 of the timer 28, an energizing circuit for thewinding 24 of the ma net 16. By closing its contacts 23, the magnet 16completes independently of the contacts 19 a locking circuit for itswinding 24 so that the magnet 16 is not deenergized by the subsequentopening of the latter contacts. The energization of the magnet 16 alsotrips the latch 18 so that the magnet 1'7 moves to its deenergizedposition and in so doing opens its contacts 19 and closes its contacts20 and 21. As soon as the contacts 20 are closed, an energizing circiutis completed for the control relay 26 through the contacts 42 whichcheck the position of latch 5, the contacts 22 of the energized magnet16 and thecontacts 39 and 40 of the timer 28. By closing its contacts43, the control relay 26 completes a circuit for the closing coil 4 toclose the circuit breaker 1. By closing its contacts 33 the controlrelay 26 also completes, through the contacts 21 of the magnet 17, anenergizing circuit for the release magnet 32 of the reclosing. device2'7.

When the circuit breaker 1 closes, the circuit of the winding 24 isinterrupted at the auxiliary contacts 25 so that the magnet 16 becomesdeenergized and opens its contacts22 and 23. Since the magnet 17 is nowin its deenergized position,

the contacts 19 thereof are open so that, if the circuit breaker 1should open immediately after its first reclosure, the magnet 16 isprevented from effecting another instantaneous reclosure.

As soon as release magnet 32 of the reclosing device 2'7 is energized,the timer 2'7 starts to rotate and after it has been in operation for apredetermined length of time, it closes the'contacts 34. If at that timethe circuit breaker 1 is open, a circuit is completed through theauxiliary contacts 25 on the circuit breaker, the winding of re- 35 lay36, contacts 34 and the contacts 39 and 40 to effect the energization ofthe relay 36. Relay 36 by closing its contacts 44 completes,independently of the contacts 34, a locking circuit for its operatingwinding so that the relay remains ener- 1 gized after the timer opensits contacts 34.

When the timer subsequently closes its contacts 35, a circuit iscompleted for the control relay 26.

This circuit includes the contacts 42 on:the latch 5, contacts 45 of therelay 36 and contacts 35, 44, 5

40 and 39 of the timer 2'7. The control relay 26 then effects, in themanner above described, the energization of the closing coil 4 so as toclose the circuit breaker l. The control relay 26 also effects theenergization of the release magnet 32 contacts 39 and 41 are taneouslyreclosed which, however, has no efl'ect at this time immediately aftereach reclosure.

because the timer is not in its normal position.

If following this reclosure the circuit breaker 1 should openimmediately after it is closed, the timer 27, in the manner abovedescribed, eifects another reclosure of the circuit breaker a prede-=termined time after the previous reclosure.

After the timer has successively closed and opened its contacts 34 and35 a predetermined number of times, it disconnects contact 39 fromcontact 40 and then connects contact 39 to contact 41. If the circuitbreaker 1 is closed at this time, a circuit is completed through thecontacts 39 and 41 and the auxiliary contacts 46 on the circuit breaker1 for the winding 27 of the magnet 17. The magnet 1'7 is then restoredto its normal position in which position it is held by the latch 18.

The contacts 39 and 40 are disconnected from each other at this time bythe timer 27' in order to prevent pumping of the circuit breaker 1 incase a permanent fault should occur while the connected together. It isobvious that if a permanent fault should occur while the contacts 39, 40and 41 are all connected together, the circuit breaker 1 would beinstanin a manner above described after each opening thereof and wouldbe open By having the contacts 40 disconnected from the contact 39, suchpumpingof the circuit breaker cannot occur because the circuit of themagnet 16 is opened while the closing circuit for the magnet 1'! iscompleted.

After the contacts 39 and i1 have been con nected together for asuflicient length of time to effect the restoration of the magnet 17 toits normal position, the timer 27' disconnects the contact 39 from thecontact'il and again con-= nects the contact 39 to the contact to. Thetimer then returns to its normal position where it is stopped by theprojection 31 engaging the stop 30.

It will be noted that several important features are obtained byemploying a control device of the type shown in Fig. 1. If, for anyreason, the circuit of the winding 24 should burn out or be interruptedor short-circuited, it is impossible to reclose the circuit breaker 1.Aiso the circuit breaker 1 cannot be closed ii the latch 18 fails tohold the magnet 17 in its energized position. Since it is necessary forthe magnet 17 to be in its energized position ,before the magnet 16 canbe energized and for the magnet 17 to be Lin its deenergized positionwhile the magnet 16 is in its energized position before the circuitbreaker 1 can be reclosed, it will be observed that we have provided avery simple, reliable and tool-proof arrangement for effecting a singleinstaneous re-= closure of a circuit breaker.

In Fig. 2 we have illustrated a modified construction of the controldevice 15. Instead of having the contacts 19, 20 and 21 held in theirnormal position by the latch 18, they are held in their operatingposition by the latch 18 which is arranged to be tripped by the winding2'? when it is energized. The magnet 16, when energized, is arranged toeffect directly the opening of the contacts 19 and closing oi. thecontacts 20 and 21. Since the windings and contacts of the con troldevice shown in Fig. 2 are connected in ex= actly the same manner as thewindings and con tacts of the control device' 15 shown in Fig. 1.further description of the device is deemed unnecessary. 1

In Fig. 3 we have shown a modification of the timer 28 whereby theinstantaneous reclosing control device 15 is rendered operative afterany time delayed reclosure, in case the circuit breaker 1 remains closedafter such a reclosure, instead of being rendered operative after aplurality of time delayed reclosures, as shown in Fig. 1. This result isobtained by designing the timer 28 so that a predetermined time aftereach completion of the circuit through the timer contacts 35, the timercontact 39 is disconnected from contact 40 and then is connected tocontact 41 so that the circuit of the winding 27 of magnet 17 iscompleted to restore the control device 15 to its normal position incase the circuit breaker 1 is closed at the time the contacts 40 and 41are connected together.

While we have, in accordance with the Patent Statutes, shown anddescribed our invention as applied to a particular system and asembodying various devices diagrammaticalLv indicated, changes andmodifications will be obvious tothose skilled in the art and we,therefore, aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of our invention.

What we claim as new and desire Letters Patent of the United States, is:

1. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for efiecting an instantaneous reclosure of saidcircuit breaker after the initial opening thereof includto secure by inga control device having a set of normally open contacts, a second set ofnormally open contacts, a set'of normally closed contacts,means'including an electromagnet for closing both 01' said sets ofnormally open contacts and ior opening said set of normally closedcontacts when said electromagnet is energized and for opening one ofsaid sets of normally open contacts only when said electromagnet issubsequently deenergized,

means responsive to the initial opening of said circuit breaker forcompleting an energizing circuit for said electromagnet through saidnormally closed contacts, and means responsive to the closing ofboth ofsaid sets of normally open contacts for eiiecting the closing of saidcircuit breaker and the deenergization of said electromagnet.

2. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for eifecting a single instantaneous reclosure ofsaid circuit breaker aiter the initial opening tliereoi including acontrol device having a set of normally open contacts, a second set ofnormally open contacts,

a set 01' normally closed contacts, means including an electromagnet forclosing both of said sets oi normally open contacts and for opening saidset of normally closed contacts when said electroet is energized and foropening one of said sets of nolly open contacts only when saidelectromagnet is subsequently deenergized. means responsive to breakerfor completing an. energizing circuit for said electromagnet throughsaid normally closed contacts, means responsive to the energization ofsaid electromagnet for completing a locking circuit therefor which isindependent of said nor mally closed contacts, and means responsive tothe closing of both of said sets of normally open contacts for effectingthe closing of said circuit breaker and the interruption of said lockingcircuit.

3. In combination, an electric circuit, a circuit breaker in saidcircuit. and means for eflecting an instantaneous reclosure of saidcircuit breaker after the initial opening thereof including the initialopening of said circuit- 4 effecting an instantaneous reclosure of saidcirtwo electromagnets, means for" normally maintaining one of saidelectromagnets in its energized position, means for effecting theenergization of the other electromagnet in response to the opening ofsaid circuit breaker only when said one of said electromagnets is in itsenergized position, means responsive to the energization of said otherelectromagnet for effecting the movement of said one of saidelectromagnets to its deenergized position and for effecting the closingof said circuit breaker, and means for subsequently restoring said oneof said electromagnets to its energized position.

4. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for effecting an instantaneousreclosure of saidcircuit breaker after the initial opening thereof including twoelectromagnets, means for normally maintaining one of saidelectromagnets in its energized position, means for effecting theenergization of the other electromagnet in response to the opening ofsaid circuit breaker only when said one of said electromagnets is inits. energized position, means responsive to the energization of saidother electromagnet for effecting the movement of said one of saidelectromagnets to its deenergized position, means for effecting theclosing of said circuit breaker only when said one of saidelectromagnets is in its deenergized position and said other magnet isenergized, means responsive to the closing of said circuit breaker foreffecting the deenergization of said other electromagnet, and means forsubsequently energizing said one of said electromagnets to restore it toits normal position.

5. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for efiecting an instantaneous reclosure of saidcircuit breaker after the initial opening thereof including twoelectromagnets, means for normally maintaining one of saidelectromagnets in its energized position, means for effecting theenergization of the other electromagnet in response to the opening ofsaid circuit breaker only when said one of said electromagnets is in itsenergized position, means responsive to the energization of said otherelectromagnet for effecting the movement of said one of saidelectromagnets to its deenergized position, means for effecting theclosing of saidcir- .cuit breaker only when said one of saidelectromagnets is in its deenergized position and said other magnet isenergized, means responsive to the closing of said circuit breaker foreffecting the deenergization of said other electromagnet, and timingmeans operative a predetermined time after the initial opening of saidcircuit breaker toeffect the energization of said one of saidelectromagnets to restore it to its normal position "and theinterruption of the energizing circuit of said other electromagnetswhile said one of said electromagnets is energized.

I 6. In combination, an electric circuit, a circuit breaker in saidcircuit, means for efiecting the opening of said circuit breaker, andmeans for cuit breaker including normally closed contacts, latchingmeans for maintaining said contacts losed, an electromagnet, meansresponsive to the opening of said circuit breaker for completing. anenergizing circuit for said electromagnet through said normallyclosedcontacts, and means,

responsive to the energization of said electromagnet for effecting theoperation of said latching meansto allow said normally closed contactsto open and for effecting the closing of said circuit breaker. a

'7. In combination, an electric circuit, a, circuit breaker in saidcircuit, means responsive to an abnormal condition on said circuit foreffecting theopening of said circuit breaker, and means for effecting aninstantaneous reclosure of said circuit breaker including normallyclosed contacts, latching means for maintaining said con- .tacts closed,an electromagnet, means responisve to the opening of said circuitbreaker for completing an energizing circuit for said electromagnetthrough said normally closed contacts, means responsive to theenergization of said electromagnet for effecting ing means to allow saidnormally closed contacts to open and for effecting the closing ,of saidcircuit breaker, and timing means controlled by the position of saidcircuit breaker for reclosing said normally closed contacts if saidcircuit breaker is in its closed position a predetermined time after theopening thereof.

8. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for efiecting a single instantaneous reclosure ofsaid circuit breaker after the initialopening thereof including normallyclosed contacts and normally open contacts held in their normalpositions by latching means, an electromagnet having normally opencontacts, means responsive to the initial opening of said circuitbreaker for completing a circuit for said electro-magnet through saidnormally closed contacts, means responsive to the energization of saidelectromagnet for effecting the tripping of said latching means toeffect the opening of said normally closed contacts and the closing ofsaid first mentioned normally open contacts, and means responsive to theclosing of both of said normally open contacts for effecting the closingof said circuit breaker and the deenergization of said electromagnet.

9. In combination, an electric circuit, a circuit breaker in saidcircuit, and means for effecting a single instantaneous reclosure ofsaid circuit breaker after the initial opening thereof includingnormally closed contacts and normally open contacts held in their normalposition by latching means, an electromagnet having normally opencontacts, means responsive to the initial opening of said circuitbreaker for completing a circuit for said electromagnet through saidnormally closed contacts, means responsive to the energization of saidelectromagnet for effecting the tripping of said latching means toeffect the opening of said normally closed contacts and the closing ofsaid first mentioned normally open contacts, means responsive to theclosing of both of said normally open contacts for effecting the closingof said circuit breaker and the deenergization of said electromagnet,and timing means controlled by the position of said circuit breaker forrestoring said normally closed contacts and said first mentionednormally open contacts to the operation of said latchcluding anelectromagnet for closing both of said sets of normally open contactsand for opening.

said set of normally closed contacts when said electromagnet isenergized and for opening one of said sets of normally open contactsonly when said electromagnet is subsequently deenergized, meansresponsive to the initial opening of said circuit breaker for completingan energizing circuit for said electromagnet through said normallyclosed contacts, means responsive to the closing of both of said sets ofnormally open contacts for efi'ecting the closing of said circuitbreaker and the deenergization of said electromagnet, and timing meansfor effecting subsequent reclosures of said circuit breaker afterrelatively long predetermined time intervals and for effecting therestoration of said normally closed contacts and the other normally opencontacts to their respective normal positions a predetermined time afterthe initial opening of said circuit breaker.

11. In combination, an electric circuit, a circuit breaker in saidcircuit, latching means for maintaining said circuit breaker closed,means for releasing said latching means to effect the opening of saidcircuit breaker, means operative after said circuit breaker opens forrestoring '7 said latching means to a position in which it is operativeto maintain said circuit breaker in its closed position and means foreilecting the reclosing of said circuit breaker only when saidlatchingmeans has been restored to said position.

12. In combination, an electric circuit, a circuit breaker in saidcircuit, latching means for maintaining said circuit breaker closed,means for releasing said latching means to efiect the opening of saidcircuit breaker, means operative after said circuit breaker opens forrestoring said latching means to a position in which'it is operative tomaintain said circuit breaker in its closed position a closing circuitfor said circuit breaker, and means responsive to the opening of saidcircuit breaker for effecting the instantaneous completion of saidclosing circuit including contacts in said closing circuit closed bysaid latching means when in its restored position.

13. In combination, an electric circuit, a circuit breaker in saidcircuit, latching means for maintaining said circuit breaker closed,means for releasing said latching means to eifect the opening of saidcircuit breaker, means operative after said circuit breaker opens forrestoring said latching means to a position in which it is operative tomaintain said circuit breaker in its closed position a closing circuitfor said circuit breaker, and a latch checking contact associated withsaid circuit breaker and controlling said closing circuit so as toprevent the completion thereof until after said latching means has beenrestored to said position.

ARVID E. ANDERSON. VERNON L. COX. FRED S. WRIGHT.

